** (emacs:5902): CRITICAL **: murrine_style_draw_box: assertion `height >= -1' failed

I have been seeing this same problem on emacs23 on Lucid.
After changing the property below from 0 to 1 in gtkrc the problem has gone.
        GtkRange::trough-under-steppers = 1

Alf, I assume that with "gtkrc" you are referring to these two files:
/usr/share/themes/Ambiance/gtk-2.0/gtkrc
/usr/share/themes/Radiance/gtk-2.0/gtkrc
The change you suggested does indeed make these warnings go away for me.

Holy Cow!! I'm like brand new to Linux (maybe 6 wks now) and I did that and it did work for me. Specifically the error I got was not precisely identical. Mine was: "** (emacs:[b]29944[/b]): CRITICAL **: murrine_style_draw_box: assertion `height >= -1' failed" This would be displayed the terminal right when launching "emacs23"

In case another super newbie, like myself, stumbles upon this I'll write out what I did exactly - perhaps it will help someone in the future. I don't know how many times I wished someone would spell it out for me like this.

After navigaging to each folder respectively, I made sure to make a copy of the original two files - just in case(located where Christian Pietsch says in post #3).

Synopsis: Navigate to the directory, make a copy of the original file, open the regular file (not the copy) with nano, edit the entry, save and close. Repeat for the second one.

Navigate to the location of the first file using:

[Code] cd /usr/share/themes/Ambiance/gtk-2.0/ [/Code]

You must log in as root to make any changes to either of these files. These file are owned by root and you will not be allowed to do anything with them without doing that.

[Code] sudo -s [/Code]

Enter password when prompted and push enter.

Then make a copy of the file just in case anything goes wrong. You'll have it to go back to but you would have to rename it to the original name for it to work. The "cp" command is used for this (only necessary if something were to go wrong and you needed to make things back the way they were).

So make a copy using:

[Code] cp gtkrc gtkrc.old [/Code]

then

[Code] nano gtkrc [/Code]

This opens the file in a text editor called nano

Once in nano press: ctrl+w (this alows you to enter a term to search in nano). Enter "GtkRange::trough-under-steppers" (without the quotes) and press enter.

Navigate to the end of this line and change the 0 to 1 as Alf says in post #2.

Press ctrl+x. You will be prompted to save the changes - press y. Press enter. This saves the changes to the file and exits nano.

Now on to the second file . . .

Navigate to the location of the second file using:

[Code] cd /usr/share/themes/Radiance/gtk-2.0/ [/Code]

Make a copy using:

[Code] cp gtkrc gtkrc.old [/Code]

then

[Code] nano gtkrc [/Code]

This opens the file in a text editor called nano

Once in nano press: ctrl+w (this alows you to enter a term to search in nano). Enter "GtkRange::trough-under-steppers" (without the quotes) and press enter.

Navigate to the end of this line and change the 0 to 1 as Alf says in post #2.

Press ctrl+x. You will be prompted to save the changes - press y. Press enter. This saves the changes to the file and exits nano.

type:

[Code] exit [/Code]

This exits root (logs you out of it)

type:

[Code] exit [/Code]

closes the terminal (unless you still need it).

Hope it might help someone in the future. I'm stoked! First time I ever did something like that. Woo Hoo!

:)